Lens driving apparatus

ABSTRACT

A lens driving apparatus with a lens portion having at least one lens, a base portion on which an image sensor detecting light coming through said lens portion can be fixed, a driving portion capable of relatively moving said lens portion in a vertical direction to a light axis of said lens portion and in a parallel direction to the light axis of said lens portion with respect to said base portion, and at least three suspension wires connecting a focus portion including said lens portion and said base portion so as to allow a relative movement. The suspension wires are arranged outside a magnet of said driving portion along the vertical direction to the light axis.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of co-pending application Ser. No.15/705,665 filed Sep. 15, 2017, which is a Divisional of applicationSer. No. 15/045,807 filed Feb. 17, 2016, which is a Divisional ofapplication Ser. No. 13/956,826 filed Aug. 1, 2013 which issued as U.S.Pat. No. 9,298,016 on Mar. 29, 2016, which is a Divisional ofapplication Ser. No. 12/948,380 filed on Nov. 17, 2010 which issued asU.S. Pat. No. 8,531,534 on Sep. 10, 2013, for which priority is claimedunder 35 U.S.C. § 120; and this application claims priority ofApplication No. 2009-262218 filed in Japan on Nov. 17, 2009 and2010-108621 filed in Japan on May 10, 2010 under 35 U.S.C. § 119, theentire contents of all of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a lens driving apparatus used for, forexample, a camera module of mobile phone and the like.

2. Description of the Related Art

For a lens driving apparatus preferably used for a camera module of amobile phone and the like, it has been suggested that a lens holder issandwiched by a pair of ring shaped springs which are arranged at anaxis direction so as to perform focusing action and the like (refer toJP Patent Laid Open No. 2004-280031).

In a lens driving apparatus according to a conventional art, a lensgroup supported by a lens holder can perform only focusing action, inorder for giving other functions such as blurring compensation and thelike to the lens driving apparatus, it was necessary to equip a lensgroup and the like for blurring compensation separately.

Therefore, in a conventional art, it has been difficult to realize alens driving apparatus which is small size having multi functions.

SUMMARY OF THE INVENTION

The present invention has been made by considering this real scene, apurpose of the invention is to provide a lens driving apparatus which issmall size having multi functions.

In order to achieve the above purpose, a lens driving apparatusaccording to the present invention comprises a lens portion having atleast one lens, a first driving portion to cause a movement of said lensportion relatively to a base portion along a vertical direction of alight axis of said lens portion, and a second driving portion to cause amovement of said lens portion relatively to said base portion along saidlight axis.

Because a lens driving portion according to the present inventioncomprises the first driving portion to cause a movement of the lensportion along the vertical direction of the light axis and the seconddriving portion to causes a movement of the lens portion along the lightaxis, the lens portion is capable to combine a lens for focus adjustingand a lens for blurring compensation. Therefore, the lens drivingapparatus according to the present invention can realize a small sizeand multi functional lens driving apparatus.

Also, for example, the lens driving apparatus according to the presentinvention may comprise a focus portion having said lens portion and saidsecond driving portion, wherein said first driving portion causes amovement of said focus portion relatively to said base portion along thevertical direction of said light axis.

Because the first driving portion in the lens driving apparatus of thepresent invention causes a movement of a whole focus portion includingthe lens portion and the second driving portion, it is possible tosimplify structures of the first driving portion and the second drivingportion. Also, the first driving portion causes a movement of the wholefocus portion along the vertical direction to the light axis, and thesecond driving portion causes a movement of the lens portion along thelight axis, as a result, the lens portion is caused a movement of threedimensional directions. The lens driving apparatus like this can beeasily controlled, as compared with the lens portion moved to threedimensional directions directly.

Also, for example, said first driving portion may include a first magnetmounted to said focus portion, and a first coil mounted to said baseportion and arranged to face said first magnet.

Because the first driving portion in the lens driving apparatuscomprises a voice coil motor composed of the first magnet and the firstcoil, the lens portion included in the focus portion can be moved alongthe vertical direction to the light axis accurately.

Also, for example, the lens driving apparatus according to the presentinvention may comprise at least three suspension wires, and said focusportion and said base portion may be connected so as to allow a relativemovement by the at least three suspension wires.

In the lens driving apparatus like this, because the focus portion andthe base portion are connected so as to allow a relative movement by theat least three suspension wires, a structure thereof is simple.

Also, for example, said focus portion may comprise a focus base able tobe moved relatively to said base portion by said first driving portionand a spring connecting said lens portion movably relatively to saidfocus base, said second driving portion may comprise a second coilequipped to said lens portion and a second magnet equipped to said focusbase and arranged to face said second coil.

The second driving portion in the lens driving apparatus like this isable to move the lens portion included in the focus portion along thelight axis accurately, because the second driving portion comprises avoice coil motor composed of the second magnet and the second coil.

Also, for example, a tip end of at least one suspension wire among atleast said three suspension wire may be electrically connected to saidsecond coil through said spring, the other end of at least said onesuspension wire may be electrically connected to an external connectionbase plate included in said base portion.

The lens driving apparatus like this has simple structure and issuitable for small size, because electric power can be supplied from thebase portion to the second coil through at least one suspension wire.

Also, said spring may include a B-spring arranged at a base side nearsaid base portion in said lens portion and a F-spring arranged at anopposite side of said base side in said lens portion, the tip end ofsaid at least one of said suspension wire may be electrically connectedto said second coil through said F-spring.

The lens driving apparatus like this is available to support the focusportion with an appropriate force by elongating the length of thesuspension wire, and is available to occupy a movable range of the focusportion.

Also, said at least three suspension wire may be composed of foursuspension wires, said first driving portion can make said focus portionmove to X-direction and Y-direction which are vertical direction to saidlight axis and mutually orthogonal, a rigidity to said X-direction ofsaid four suspension wires and a rigidity to said Y-direction of saidfour suspension wires may be substantially equal, also, said at leastthree suspension wires may have a substantial circular shaped crosssection respectively.

The lens driving apparatus like this is easy to control the firstdriving portion in blurring action and the like, because primaryresonance frequencies of the X-direction and the Y-direction becomeequal, when driving the focus portion by the first driving portion.Also, it becomes easy to assemble suspension wires, by forming the crosssection of the suspension wire in a substantial circular shape, becauserigidity of a suspension wire 31 becomes substantially equal withrespect to a rotating direction which an axis of the suspension wire iscenter.

Also, for example, the lens driving apparatus according to the presentinvention may be equipped to said focus portion, and may be arrangedbetween said first magnet and said second magnet, and may include amagnet holding plate composed of a magnetic body.

The magnet holding plate arranged between the first magnet and thesecond magnet shutoff magnetism between the first magnet and the secondmagnet so that interference of respective magnetic field can beprevented. Therefore, the lens driving apparatus including the magnetholding plate like this is capable to drive the lens accurately.

For example, said magnet holding plate may have a ring shape whereincircumference is substantially rectangular, said first magnet may becomposed of four rod-like magnets which are arranged at positionscorresponding to respective sides of said magnet holding plate viewingfrom a direction of said light axis, said second magnet may be composedof four individual piece magnets arranged at positions corresponding torespective corners of said magnet holding plate viewing from a directionof said light axis.

By composing the first magnet with the rod-like magnets arranged atpositions corresponding to respective sides of the magnet holding plate,the first driving portion becomes possible to generate further largerdriving force. Against this, by composing the second magnet with theindividual piece of magnets arranged at positions corresponding torespective corners of said magnet holding plate, a lens supportingdevice becomes capable to include further larger diameter lens.Therefore, the lens driving apparatus like this is suitable fordownsizing further.

Preferably, an image sensor to detect light which comes through saidlens portion is arranged on said base portion. By fixing the imagesensor on the base portion, it becomes capable to move the lens portionto a direction vertical to the light axis or to a direction along thelight axis to the image sensor. Namely, the lens portion is supported tocause a free movement to directions of three axes (three dimensions) tothe image sensor.

Note that, in a structure wherein the image sensor is mounted to thelens portion (movable portion) and not to the base portion (fixedportion), one end of a flexible print circuit (FPC) must be connected tothe movable portion and another end of the FPC must be connected to thefixed portion which is necessary, in order to take an output signal fromthe image sensor to the outside. In the structure like this, because abetweenness of the fixed portion and the movable portion is connected tothe FPC, there is a risk to prevent movement of the lens portion whichis a movable portion to the fixed portion, therefore, there is a riskthat accuracy of blurring control tends to be lowered. Also, due tobending or extending of the FCP in response to the movement of the lensportion, a noise signal is generated so that there is a risk to lowerthe accuracy of the blurring control in this point.

Against this, in the present invention, it is not necessary to connectthe betweenness of the movable portion and the fixed portion by FPC fortransferring an image data by fixing the image sensor to the baseportion (fixed portion). As a result, the movement of the lens portionwhich is movable portion to the fixed portion can be made smoothly aswell as a noise signal generated by bending of the FPC and the like canbe prevented so that the accuracy of blurring control can be increased.Also, by fixing the image sensor to the base portion (fixed portion),assembling the lens driving apparatus can become easier whichcontributes for reducing manufacturing cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a disassembled camera unit including alens driving apparatus according to one embodiment of the presentinvention.

FIG. 2 is a partial assembly view showing arrangement of components neara blurring compensation voice coil motor in the camera unit shown inFIG. 1.

FIG. 3 is a perspective view of the camera unit shown in FIG. 1.

FIG. 4 is a schematic plane view for explaining a constitution of theblurring compensation voice coil motor included in the camera unit shownin FIG. 3.

FIG. 5 is a schematic cross sectional view showing the camera unit shownin FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

FIG. 1 is a disassembled perspective view of a camera unit 44 includinga lens driving unit 42 according to one embodiment of the presentinvention. The camera unit 44 is configured by the lens driving unit 42and an image taking element unit 46. Note that, in explanation of thecamera unit 44, as shown in the coordinate described in FIG. 1 to FIG.5, it will be specified that along a direction of a light axis of a lensportion 21 included in the lens driving unit 42, a direction from animage sensor 11 to the lens portion 21 is defined as a positivedirection of Z-axis, vertical directions to a light axis L of the lensportion 21 are defined as X-axis direction and Y-axis direction. Notethat, the X-axis, Y-axis and Z-axis are vertical each other.

The image taking element unit 46 comprises a filter 13, a bracket 12, animage sensor 11, an image sensor base plate 10 and the like. The imagesensor 11 is composed of a solid image taking element such as CCD, CMOSand the like, and it generates an image signal by photoelectricconversion. The image sensor 11 is mounted on a surface of Z-axispositive direction side of the image sensor base plate 10. The imagesignal generated at the image sensor 11 is transmitted to an arithmeticsection and an information storage section through the image sensor baseplate 10.

The bracket 12 and the filter 13 are arranged at the Z-axis positivedirection side of the image sensor 11. The bracket 12 is fixed to theimage sensor base plate 10, a light receiving surface of the imagesensor 11 is protected by the bracket 12 and the filter 13. Arectangular shaped through hole is formed on the bracket 12 so as topass through an image light. The filter 13 is composed of a transparentmaterial and is mounted on the bracket 12 so as to block the throughhole of the bracket 12.

A lens driving unit 42 is arranged at a Z-axis positive direction sideof an image taking element unit 46. The lens driving unit 42 accordingto the present embodiment comprises a focus portion 20 including a lensportion 21 and an AF voice coil motor 38, a magnet holding plate 34, ablurring compensation voice coil motor 39, a suspension wire 31 and abase section 40.

As shown in FIG. 1, the base portion 40 is arranged at the Z-axispositive direction side of the bracket 12. The base portion 40 comprisesa unit board 33 and a circuit board 32. It is preferable that the unitboard 33 have a sufficient strength so that the circuit board 32 and thesuspension wire 31 and the like which are arranged to the Z-axispositive direction side of the unit board 33 can be supported. As formaterials of the unit board 33, although it is not particularly limited,for example, a resin material such as LCP (Liquid Crystal Polymer) andthe like can be used. The unit board 33 is fixed to the bracket 12. Thebase portion 40, which includes the unit board 33, is equipped to theimage taking element unit 46, which includes the image sensor 11, withfixing so as not to allow a relative movement to the image sensor 11.

The circuit board 32 comprises a wiring for transmitting electricalsignals to the AF voice coil motor 38 and a blurring compensation voicecoil motor 39. The circuit board 32 is composed of, for example, FPC(Flexible Printed Circuit) and the like. The circuit board 32 is fixedto the unit board 33 by adhering and the like and is supported by theunit board 33.

The circuit board 32 is electrically connected to a driving controlsection (not shown in drawings) which is provided at the lens drivingunit 42 externally. Namely, the circuit board 32 has a role of anoutside connecting base plate to relay electronic components in the lensdriving unit 42 and the driving control section. The AF voice coil motor38 and a blurring compensation voice coil motor 39 are driven andcontrolled by the driving control section so that the auto focus actionand blurring compensation action can be realized appropriately. Forexample, a control signal from the driving control section istransmitted to an AF coil 23 (second coil), a X-direction blurringcompensation coil (first coil) 36 x and a Y-direction blurringcompensation coil (first coil) 36 y through the circuit board 32.

A X-direction position sensor 35 x and a Y-direction position sensor 35y are provided on the circuit board 32. The X-direction position sensor35 x and Y-direction position sensor 35 y detect a relative position ofthe focus portion 20 to the base portion 40. The X-direction positionsensor 35 x and Y-direction position sensor 35 y are composed of, forexample, a hall element and the like. The X-direction position sensor 35x and Y-direction position sensor 35 y performs position detecting forthe focus portion 20 by detecting a magnetic field variation caused bymoving a X-direction blurring compensation magnet 37 x and a Y-directionblurring compensation magnet 37 y which are equipped to the focusportion 20.

The suspension wire 31 connects the base portion 40 and the focusportion 20 so as to allow a relative movement. The lens driving unit 42according to the present embodiment comprises four suspension wires 31.Although a material for the suspension wire 31 is not particularlylimited, phosphor bronze is preferable.

Also, number of the suspension wire 31 used for the lens driving unit 42is preferably 3 or more, in view of connecting and supporting the baseportion 40 and the focus portion 20 with good balance. In the presentembodiment, the suspension wire 31 is provided at four corners of thelens driving unit 42 having an about rectangular shape viewing from adirection of the Z-axis. One tip end of the respective suspension wire31 is fixed to the circuit board 32 or the unit board 33 of the baseportion 40, a base end of the respective suspension wire 31 is fixed toa cap 27 or a F-spring 24 included in the focus portion 20. By fixingthe suspension wire 31 to the cap 27 or F-spring 24 which are providedat the Z-axis positive direction side tip end of the focus portion 20,the focus portion 20 can be supported by an appropriate force withmaking elongated length of the suspension wire 31, a movable area of X-Ydirection can be enlarged.

Also, in the present embodiment, the base portion 40 and the focusportion 20 are connected by four suspension wires 31, these foursuspension wires have substantially equal rigidity to the X-axisdirection and to the Y-axis direction. By making such constitution,primary resonance frequencies of the X-axis direction and the Y-axisdirection becomes substantially equal, when the focus portion 20 isdriven by a following mentioned blurring compensation voice coil motor39, a relative positioning control of the focus portion 20 by theblurring compensation voice coil motor 39 becomes easier. Also, bymaking a cross section of the suspension wire 31 in a circular shape ora substantially circular shape which is close to the circular shape suchas polygonal shape and the like, the rigidity of the suspension wire 31becomes substantially uniform with respect to a rotating direction whosecenter is an axis of the suspension wire 31, it becomes easy to assemblethe suspension wire 31.

Also, in the lens driving unit 42 according to the present embodiment,tip ends of two suspension wires 31 of the four suspension wires 31 areelectrically connected to the AF coil 23 through the F-spring 24. Also,base ends of these two suspension wires 31 are electrically connected tothe circuit board 32.

Namely, in the present embodiment, the F-spring 24 is electricallydivided in two. One tip end of the AF coil 23 shown in FIG. 1 iselectrically connected to one side of the divided F-spring 24, and iselectrically connected to one tip end of the suspension wire 31 throughone side of the F-spring 24. Contrary to this, the base end of the AFcoil 23 is electrically connected to the other side of the dividedF-spring 24, and is electrically connected to one tip end of othersuspension wire 31, which is different from the suspension wire 31connected to the AF coil 23 through the other side of the F-spring 24.Therefore, the lens driving unit 42 according to the present embodimentis able to provide electric power from the circuit board 32 of the baseportion 40 to the AF coil 23 through the two suspension wires 31.

The blurring compensation voice coil motor 39 is provided on the Z-axispositive direction side of the base portion 40. The blurringcompensation voice coil motor 39 causes a movement of the lens portion21 to relatively to the base portion 40, along a direction which isvertical to the light axis L of the lens portion 21. The blurringcompensation voice coil motor 39 according to the present embodimentcauses a movement of the lens portion 21 relatively to the base portion40 by moving the whole focus portion 20 which includes the lens portion21 and the AF voice coil motor 38.

The blurring compensation voice coil motor 39 comprises a X-directionblurring compensation magnet 37 x and a Y-direction blurringcompensation magnet 37 y which are equipped to the focus portion 20through the magnet holding plate 34, a X-direction blurring compensationcoil 36 x and a Y-direction blurring compensation coil 36 y which areequipped to the base portion 40. The x-direction blurring compensationcoil 36 x is arranged at the Z-axis negative direction side of theX-direction blurring compensation magnet 37 x so as to face theX-direction blurring compensation magnet 37 x. Also, the Y-directionblurring compensation coil 36 y is arranged at the Z-axis negativedirection side of the Y-direction blurring compensation magnet 37 y soas to face the Y-direction blurring compensation magnet 37 y.

The blurring compensation voice coil motor 39 comprises four coils 36 x,36 y constituted by the two X-direction blurring compensation coil 36 xand the two Y-direction blurring compensation coil 36 y, and fourmagnets 37 x, 37 y constituted by the two X-direction blurringcompensation magnet 37 x and the two Y-direction blurring compensationmagnet 37 y. To the respective coils 36, electric current for drivingthe blurring compensation voice coil motor 39 is supplied from thecircuit board 32.

The magnet holding plate 34 is arranged at the Z-axis positive directionside of the blurring compensation voice coil motor 39. The magnetholding plate 34 is mounted to the focus portion 20, in the presentembodiment, it is fixed to a magnet supporting member 25. The magnetholding plate 34 is constituted by a magnetic body, for example iron,stainless and the like.

The magnet holding plate 34 is arranged, as shown in FIG. 1, between theAF magnet 26 arranged at the Z-axis positive direction side of themagnet holding plate 34 and the X-direction and Y-direction blurringcompensation magnets 37 x, 37 y arranged at the Z-axis negativedirection side of the magnet holding plate 34. Therefore, the magnetholding plate 34 prevents interference of magnetic fields of each otherby blocking magnetism occurred between the magnets 37 x, 37 y includedin the blurring compensation voice coil motor 39 and the magnet 26included in the AF voice coil motor 38.

In the present embodiment, the magnet holding plate 34 has a ring shapein which a circumference thereof is substantially a rectangular shape.Also, the magnets 37 x, 37 y included in the blurring compensation voicecoil motor 39 are composed of a rod-like magnet, the respective magnets37 x, 37 y are arranged at positions corresponding to respective sidesof the magnet holding plate 34.

FIG. 2 is a partial assembly view showing an arrangement of componentsnear the blurring compensation voice coil motor 39 in the camera unit 44shown in FIG. 1. The magnets 37 x, 37 y and coils 36 x, 36 y included inthe blurring compensation voice coil motor 39 shown in FIG. 1 arearranged as shown in FIG. 2, after the camera unit 44 is assembled. Notethat the focus portion 20 is not shown in FIG. 2.

In FIG. 2, the magnet holding plate 34, the X-direction and Y-directionblurring compensation magnets 37 x, 37 y fixed to the magnet holdingplate 34 are not fixed to other components shown in FIG. 2. Namely, inthe camera unit 44 shown in FIG. 1, the blurring compensation voice coilmotor 39 causes a movement of the focus portion 20 arranged at theZ-axis positive direction side of the magnet holding plate 34 relativelyto a direction along a XY plane against the image taking element unit 46and the base portion 40.

As shown in FIG. 1, the focus portion 20 is arranged at the Z-axispositive direction side of the magnet holding plate 34. The focusportion 20 comprises the lens portion 21, the AF voice coil motor 38,the F-spring 24, a B-spring 29, the focus base 48, a coil holder 22 andthe like.

The focus base 48 according to the present embodiment is constituted bya magnet supporting member 25 and the cap 27. An AF magnet 26 includedin the AF voice coil motor 38 is fixed to the magnet supporting member25. Also, the X-direction blurring compensation magnet 37 x and theY-direction blurring compensation magnet 37 y are equipped to the magnetsupporting member 25 through the magnet holding plate 34.

Also, the cap 27 and the magnet supporting member 25 are, as shown inFIG. 3, fixed each other after assembling the camera unit 44 toconstitute a focus base 48. Note that, the cap 27 may be equipped to themagnet supporting member 25 through the F-spring 24 and an insulationsheet 30 shown in FIG. 1.

As shown in FIG. 1, the lens portion 21 and the AF voice coil motor arereceived in the focus base 48. The lens portion 21 includes at least onelens, and forms an image by the image light on a light receiving surfaceof the image sensor 11 arranged at the Z-axis positive direction side ofthe lens portion 21.

The AF voice coil motor 38 causes the lens portion 21 relatively movingto the base portion 40 along the light axis L of the lens portion 21.Here, the AF voice coil motor 38 according to the present embodimentcauses a movement of the lens portion 21 relatively to the light axisdirection against the focus base 48. However, as mentioned below, thefocus base 48 is connected and supported by the suspension wires 31 tothe base portion 40. Therefore, the AF voice coil motor 38 can make thelens portion 21 move relatively to the base portion 40 and the imagesensor 11 consequently by causing a movement of the lens portion 21relatively to the focus base 48.

The AF voice coil motor 38 comprises an AF coil 23 equipped to the lensportion 21 and an AF magnet 26 equipped to the focus base 48. The AFmagnet 26 is, as shown in FIG. 1, fixed to the magnet supporting member25, and is arranged to face the AF coil 23 after assembling. The AFmagnet 26 is constituted by four individual piece magnets, eachindividual piece magnets are arranged as surrounding the AF magnet 26along a circumference direction of the lens portion 21. The individualpiece magnets to constitute the AF magnet 26 are arranged at positionscorresponding to respective corners of said magnet holding plate 34viewing from a direction of said light axis (Z-axis direction).

Although the AF coil 23 may be fixed to the lens portion 21 directly, itmay be fixed through a coil holder 22 as it is like the lens drivingunit 42 according to the present embodiment. The coil holder 22 has ahollow cylindrical shape and includes a portion to fix the lens portion21 and a portion to fix the AF coil 23. The AF coil 23 which ispolygonal (octagonal) can be attached certainly to the cylindrical shapelens portion 21 by the coil holder 22.

The lens driving unit 42 according to the present embodiment comprisesthe B-spring 29 equipped to a base portion 40 side in the lens portion21(Z-axis negative direction side) and the F-spring 24 equipped to anopposite side (Z-axis positive direction side) to the base portion 40 inthe lens portion 21. The B-spring 29 and the F-spring 24 connect thefocus base 48 and the lens portion 21 as relatively movable along thelight axis direction L of the lens portion 21, as shown in FIG. 5. TheF-spring 24 comprises, as shown in FIG. 1, an outer circumferentialportion 24 a fixed with the focus base 48 and an inner circumferentialportion 24 b fixed with the lens portion 21. The outer circumferentialportion 24 a may be fixed to the magnet supporting member 25 or the cap27 directly to compose the focus base 48 or may be fixed to the focusbase 48 indirectly by fixing to the AF magnet 26 which is fixed to themagnet supporting member 25 through an insulation sheet 30.

Although the inner circumferential portion 24 b may be fixed to the lensportion 21 directly, it may be fixed to the lens portion 21 indirectlyby fixing to the coil holder 22 which is fixed to the lens portion 21.The B-spring 29 is fixed to the focus base 48 and the lens portion 21directly or indirectly as similar with the F-spring 24. The B-spring 29and the F-spring 24 are preferably constituted by a resilient materialso as to make relatively movable of the focus base 48 and the lensportion 21 along the light axis direction of the lens portion 21.

The F-spring 24 in the present embodiment is constituted by a resilientmaterial having conductive characteristic. Although a material toconstitute the F-spring 24 is not particularly limited, for example,metallic material such as copper, beryllium or allows including thereofmay be used. The inner circumferential portion 24 b of the F-spring 24is electrically connected to the AF coil 23 fixed to the coil holder 22.Therefore, the lens driving unit 42 is capable to supply electric powerfrom the circuit board 32 of the base portion 40 to the AF coil 23through the two suspension wires 31 and the F-spring 24.

The one tip end of the AF coil 23 shown in FIG. 1 is electricallyconnected to one of the divided F-spring 24, and is electricallyconnected to the one tip end of the suspension wire 31 through the oneside of the F-spring 24. Contrary to this, base end of the AF-coil 23 iselectrically connected to another end of the divided F-spring 24, and iselectrically connected to the base end of the suspension wire 31 whichis different from the suspension wire 31 to which the AF-coil isconnected, through the other side of the F-spring 24. Therefore, thelens driving unit 42 according to the present embodiment is capable tosupply electric power from the circuit board 32 of the base portion 40to the AF coil 23 through the two suspension wires 31. Note that, incase that the electric power is supplied to the AF coil 23 through theF-spring, it is preferably to sandwich the insulation sheet 30 betweenthe magnet and the F-spring 24.

The cap 27 is mounted to the Z-axis positive direction side of themagnet supporting member 25. The F-spring 24, the AF voice coil motor38, the lens portion 21 and the like are received at the Z-axis negativedirection side of the cap 27. The base end of the suspension wire 31 isfixed to the cap 27 through the F-spring 24 or directly. Note that, thecamera unit 44 may comprise a cover 28 for covering the image takingelement unit 46 and the lens driving unit 42.

FIG. 3 is a perspective view of the camera unit 44 shown in FIG. 1 afterassembled. Note that, the cover 28 in FIG. 1 is not shown in FIG. 3. Anouter shape of the lens driving unit 42 is a rectangular shape, thesuspension wires 31 are arranged to four corners of the lens drivingunit 42. The one tip end of the suspension wire 31 is fixed to the baseportion 40, as shown in FIG. 3, the base end of the suspension wire 31is fixed to the magnet supporting member 25 of the focus base 48 or tothe cap 27.

Because the suspension wire 31 supports a betweenness of the focus base48 and the base portion 40, the X-direction blurring compensation magnet37 x mounted to the focus base 48 and the X-direction blurringcompensation coil 36 x are arranged to the Z-axis direction as facingeach other with sandwiching a slight space. Similarly, the Y-directionblurring compensation magnet 37 y and the Y-direction compensation coil36 y are also arranged to the Z-axis direction as facing each other withsandwiching a slight space.

FIG. 4 is a schematic plane view for explaining a constitution of theblurring compensation voice coil motor 39, a positioning relation of theblurring compensation voice coil motor 39 and the image sensor 11 inFIG. 1 is observed from the Z-axis positive direction side. The twopairs of X-direction blurring compensation magnets 37 x and coils 36 xwhich are arranged as sandwiching the image sensor 11 to the X-axisdirection cause to relative move the whole body of the focus portion 20shown in FIG. 3 to the X-axis direction against the base portion 40.

Also, as shown in FIG. 4, the two pairs of Y-direction blurringcompensation magnets 37 y and coils 36 y which are arranged assandwiching the image sensor 11 to the Y-axis direction cause to amovement of whole body of the focus portion 20 shown in FIG. 3relatively to the Y-axis direction against the base portion 40. Thereby,the blurring compensation voice coil motor 39 is capable to make themovement of the whole body of focus portion 20 shown in FIG. 3relatively to arbitral directions along the XY plane to the base portion40.

As shown in FIG. 3 and FIG. 4, the X-direction position sensor 35 xmounted to the base portion 40 is arranged to the X-direction blurringcompensation magnet 37 x mounted to the focus base 48 as facing eachother with sandwiching a slight space to the Z-axis direction which issimilar with the X-direction blurring compensation coil 36 x. Also, theY-direction position sensor 35 y is arranged to the Y-direction blurringcompensation magnet 37 y as facing each other with sandwiching a slightspace to the Z-axis direction each other.

The drive control section (not shown) to control the lens driving unit42 shown in FIG. 1 detects a position of the focus portion 20 or thelens portion 21 based on detected signals of the X-direction positionsensor 35 x and the Y-direction position sensor 35 y. The lens drivingunit 42 according to the present embodiment can perform high accurateblurring compensation operation by detecting the position of the lensportion 21 and driving the blurring compensation voice coil motor 39 onthe basis of this.

FIG. 5 is a schematic cross sectional view of the camera unit 44observed by a cross section through which the light axis L and a V-Vline shown in FIG. 3. In FIG. 5, a left side portion from the light axisL shows a cross section through which the light axis L and the XY planesurface are passing, a right side portion from the light axis L shows across section through which the light axis L and the suspension wire 31are passing. Note that, FIG. 5 is a schematic view for specifying thedriving motion of the lens portion 21, shapes of each member are shownas simplified, also indication of some parts are omitted.

As shown in FIG. 5, the lens portion 21 is supported by the F-spring 24and the B-spring 29 as relatively movable along the light axis L to thefocus base 40. The lens portion 21 is driven by the AF voice coil motor38 so as to make a movement relative to the focus base 48 along thelight axis L. The AF voice coil motor 38 comprises The AF coil 23equipped to the lens portion 21 through the coil holder 22 and AF magnet26 equipped to the magnet supporting member 25 of the focus base 48.

In this manner, the lens driving unit 42 according to the presentembodiment connects the focus base 48 and the lens portion 21 asrelatively movable by using the F-spring 24 and the B-spring 29, and theAF voice coil motor 38 is arranged between the lens portion 21 and thefocus base 48. Thereby, the lens driving unit 42 according to thepresent embodiment is capable to cause a moving of the lens portion 21along the light axis L accurately, in spite of having very simplestructure.

As shown in FIG. 5, in the lens driving unit 42 according to the presentembodiment, the lens portion 21, the AF voice coil motor 38 and thefocus base 48 constitute the focus portion 20 which is capable toperform focus action. Namely, the AF voice coil motor 38 of the focusportion 20 is capable to adjust the focal distance of camera unit 44 bymaking a movement of the lens portion 21 relatively to the light axis Lagainst the base portion 40.

The focus portion 20 is supported as relatively movable to the baseportion 40 along the vertical direction to the light axis L by the foursuspension wires 31. The focus portion 20 is driven by the blurringcompensation voice coil motor 39 so as to make a movement along thevertical direction relatively to the light axis L against the baseportion 40. The blurring compensation voice coil motor 39 comprises theX-direction and the Y-direction blurring compensation magnets 37 x, 37 ywhich are equipped to the focus portion 20 through the magnet holdingplate 34, and the X-direction and Y-direction blurring compensationcoils 36 x, 36 y which are equipped to the base portion 40.

In this manner, the lens driving unit 42 according to the presentembodiment connects the focus portion 20 and the base portion 40 asrelatively movable by using four suspension wires 31, and the blurringcompensation voice coil motor 39 is arranged between the focus portion30 and the base portion 40. Thereby, the lens driving unit 42 accordingto the present embodiment is capable to cause a movement of the lensportion 21 along the light axis L accurately, in spite of having verysimple structure.

Therefore, the lens driving unit 42 is capable to perform blurringcompensation by using the blurring compensation voice coil motor 39 soas to compensate the blurring added to the camera unit 44 according todrive the lens portion 21. Further, in the lens driving unit 42according to the present embodiment, the blurring compensation voicecoil motor 39 causes a movement of the whole focus portion 20 to thedirection vertical to the light axis L. Therefore, in the lens drivingunit 42 according to the present embodiment, one lens portion 21 canserve both as lens for focusing which is used for auto-focus etc. andlens for the blurring compensation. Therefore, the lens driving unit 42according to the present embodiment is capable to reduce number ofcomponents and simplify its structure, having high function andappropriate for downsizing.

As shown in FIG. 5, the X-direction and the Y-direction blurringcompensation magnets 37 x, 37 y are equipped to the base portion of theZ-axis negative direction side of the focus portion 20 through themagnet plate 34. The magnet holding plate 34 is composed of a magneticbody and is arranged between the X-direction and the Y-directionblurring compensation magnets 37 x, 37 y and the AF magnet 26.

The magnet holding plate 34 blocks magnetism between the X-direction andthe Y-direction blurring compensation magnets 37 x, 37 y and the AFmagnet 26 so that interference of each magnetic field can be protected.Therefore, the lens portion 21 can be driven accurately by the lensdriving unit 42 according to the present embodiment. Also, it ispossible to locate the X-direction and the Y-direction blurringcompensation magnets 37 x, 37 y and the AF magnet 26 adjacently by theblocking effect of the magnet holding plate 34, it is appropriate fordownsizing, in view of this.

As shown in FIG. 1 and FIG. 5, the AF magnet 26 is composed of fourindividual piece of magnets arranged at positions corresponding torespective corners of the magnet holding plate 34. The AF coil 23 mustbe arranged, as shown in FIG. 5, at an inner circumferential side of theAF magnet 26. However, the lens driving unit 42 according to the presentembodiment becomes capable to include the lens portion 21 having largerdiameter by arranging the AF magnet 26 at the corners so that it isappropriate for downsizing.

Also, as shown in FIG. 1, FIG. 4 and FIG. 5, the X-direction and theY-direction blurring compensation magnets 37 x, 37 y are composed offour rod-like magnets which are arranged at positions corresponding torespective sides of the magnet holding plate 34. Here, the X-directionand the &-direction blurring compensation magnet coils 36 x, 36 y arearranged at the Z-axis negative direction side to the X-direction andthe Y-direction blurring magnet 37 x, 37 y, not on an innercircumferential side.

Therefore, it is possible to increase a driving force by enlarging afacing area of the magnets and the coils in the blurring compensationvoice coil motor 39 with maintaining the whole body as small, from thispoint, it is appropriate for downsizing too. Also, since the blurringcompensation voice coil motor 39 causes a movement of whole body of thefocus portion 20, it is preferable to have larger driving force thanthat of the AF voice coil motor 38. Note that, the X-direction blurringcompensation magnet 37 x is magnetized in-face two pole to theX-direction corresponding to the X-direction blurring compensation coil36 x (refer to FIG. 5), similarly, the Y-direction blurring compensationmagnet 37 y is magnetized in-face two pole to the Y-directioncorresponding to the Y-direction blurring compensation coil 36Y.

Also, tip ends of the two suspension wires 31 among the four suspensionwires 31 shown in FIG. 1 are electrically connected to the AF coil 23through the F-spring 24 shown in FIG. 5. Also, base ends of the twosuspension wires 31 are electrically connected to the circuit board 32.Therefore, the lens driving unit 42 according to the present embodimentis capable to supply electric power from the circuit board 32 of thebase portion 40 to the AF coil 23 through the two suspension wires 31,and has simple structure as well as appropriate for downsizing.

Further, in the present embodiment, the lens portion 21 is supported tothe image sensor 11 as freely movable to directions of three axis (threedimensional) by fixing the image sensor 11 to the base portion 40(fixing portion). Also, in the present embodiment, it is not necessaryto connect a betweenness of the movable portion and the fixed portion byFPC for transferring an image data, it is possible to make smooth movingthe focus portion 20 which is the movable portion to the image sensor11, and it is possible to prevent a noise signal caused by bending andthe like of the FPC so that accuracy of the blurring compensationcontrol can be increased. Also, it becomes easy to assemble the lensdriving unit 42 by fixing the image sensor 11 to the base portion 40(fixed portion) which contributes for reducing manufacturing cost.

Other Example

In the above mentioned embodiment, although the blurring compensationvoice coil motor 39 causes to move the lens portion 21 and the AF voicecoil motor 38, as for the lens driving unit according to the presentinvention, it is not limited thereto. For example, a lens driving unitmay be that available that an AF voice coil motor causes to move thelens portion 21 and a blurring compensation voice coil motor. Also, inthe above mentioned embodiment, as for the driving portion to move thelens portion 21, although a voice coil motor is adopted, a drivingportion other than the voice coil motor may be adopted.

The invention claimed is:
 1. An optical driving apparatus comprising: amovable portion including a holder for holding an optical componenthaving a light axis; a base portion to which the movable portion isrelatively movable; a driving portion for driving the holder so as torelatively move the holder to the base portion; a plate-like springextending to a plane vertical to the light axis, the plate-like springbeing connected to the holder and electrically connected to the drivingportion, and a position detection portion for detecting a movement ofthe movable portion to the base portion, wherein the position detectionportion is placed on the base portion, and wherein the movable portionand the position detection portion partially overlap each other viewingfrom the light axis.
 2. The optical driving apparatus according to claim1, further comprising a magnetic portion facing the position detectionportion, wherein the magnetic portion is movable to the positiondetection portion.
 3. The optical driving apparatus according to claim2, wherein the magnetic portion and the position detection portion atleast partially overlap each other viewing from the light axis.
 4. Theoptical driving apparatus according to claim 1, further comprising acircuit portion, wherein the position detection portion is electricallyconnected to the base portion.
 5. The optical driving apparatusaccording to claim 1, wherein the driving portion is electricallyconnected to the circuit portion.
 6. The optical driving apparatusaccording to claim 1, further comprising a resilient portion, whereinthe movable portion is electrically connected to the base portionthrough the resilient portion.
 7. The optical driving apparatusaccording to claim 1, wherein the base portion includes an openingthrough which the light axis passes.
 8. The optical driving apparatusaccording to claim 1, wherein the base portion has a surface at leastpartially overlapping the position detection portion viewing from aperpendicular direction to the light axis.
 9. The optical drivingapparatus according to claim 8, wherein the circuit portion is directlycontacted with the surface.
 10. The optical driving apparatus accordingto claim 1, further comprising an image sensor receiving a light alongthe light axis, wherein a shortest distance between the image sensor andthe movable portion in the light axis is larger than that between theposition detection portion and the movable portion in the light axis.11. The optical driving apparatus according to claim 1, furthercomprising a bracket with an opening through which the light axispasses, wherein the image sensor and the bracket overlap each otherviewing from a perpendicular direction to the light axis.
 12. Theoptical driving apparatus according to claim 7, wherein the movableportion further includes a lens holder with a housing space for housingthe optical component, and a maximum size of the housing space isdifferent from that of the opening in a perpendicular direction to thelight axis.
 13. The optical driving apparatus according to claim 12,wherein the maximum size of the housing space is smaller than that ofthe opening in a perpendicular direction to the light axis.
 14. Anoptical driving apparatus comprising: a movable portion including aholder for holding an optical component having a light axis; a baseportion to which the movable portion is relatively movable; a drivingportion for driving the holder so as to relatively move the holder tothe base portion; a spring holding the holder movably relative to thebase portion, and a position detection portion for detecting a movementof the movable portion to the base portion, wherein the positiondetection portion is placed on the base portion, wherein the movableportion and the position detection portion partially overlap each otherviewing from the light axis, and wherein the spring and the positiondetection portion partially overlap each other viewing from the lightaxis.
 15. An optical driving apparatus comprising: a movable portionincluding a holder for holding an optical component having a light axis;a base portion to which the movable portion is relatively movable; adriving portion for driving the holder so as to relatively move theholder to the base portion; a spring holding the holder movably relativeto the base portion, and a position detection portion for detecting amovement of the movable portion to the base portion, wherein theposition detection portion is placed on the base portion, wherein themovable portion and the position detection portion partially overlapeach other viewing from the light axis, and wherein the spring and theposition detection portion are arranged at a different position to eachother along the optical axis.
 16. An optical driving apparatuscomprising: a movable portion including a holder for holding an opticalcomponent having a light axis; a base portion to which the movableportion is relatively movable; a driving portion for driving the holderso as to relatively move the holder to the base portion; and a positiondetection portion for detecting a movement of the movable portion to thebase portion, wherein the position detection portion is placed on thebase portion, wherein the movable portion includes a magnetic portion,wherein the position detection portion detects a change of a magneticfield due to a movement of the magnetic portion of the movable portion,and wherein the movable portion and the position detection portionpartially overlap each other viewing from the light axis.